subroutine fpfrno(maxtr,up,left,right,info,point,merk,n1, * count,ier) c subroutine fpfrno collects the free nodes (up field zero) of the c triply linked tree the information of which is kept in the arrays c up,left,right and info. the maximal length of the branches of the c tree is given by n1. if no free nodes are found, the error flag c ier is set to 1. c .. c ..scalar arguments.. integer maxtr,point,merk,n1,count,ier c ..array arguments.. integer up(maxtr),left(maxtr),right(maxtr),info(maxtr) c ..local scalars integer i,j,k,l,n,niveau c .. ier = 1 if(n1.eq.2) go to 140 niveau = 1 count = 2 10 j = 0 i = 1 20 if(j.eq.niveau) go to 30 k = 0 l = left(i) if(l.eq.0) go to 110 i = l j = j+1 go to 20 30 if (i.lt.count) go to 110 if (i.eq.count) go to 100 go to 40 40 if(up(count).eq.0) go to 50 count = count+1 go to 30 50 up(count) = up(i) left(count) = left(i) right(count) = right(i) info(count) = info(i) if(merk.eq.i) merk = count if(point.eq.i) point = count if(k.eq.0) go to 60 right(k) = count go to 70 60 n = up(i) left(n) = count 70 l = left(i) 80 if(l.eq.0) go to 90 up(l) = count l = right(l) go to 80 90 up(i) = 0 i = count 100 count = count+1 110 l = right(i) k = i if(l.eq.0) go to 120 i = l go to 20 120 l = up(i) j = j-1 if(j.eq.0) go to 130 i = l go to 110 130 niveau = niveau+1 if(niveau.le.n1) go to 10 if(count.gt.maxtr) go to 140 ier = 0 140 return end